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  • Letter
  • Open Access

Composition of electron temperature gradient driven plasma turbulence in JET-ILW tokamak plasmas

B. Chapman-Oplopoiou1, J. Walker2, D. R. Hatch3, T. Görler4, and JET contributors5

  • 1UKAEA, Culham Science Centre, Abingdon, OX14 3DB, United Kingdom
  • 2University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
  • 3Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712, USA
  • 4Max Planck Institute for Plasma Physics, Boltzmannstr. 2, 85748 Garching, Germany
  • 5See the author list of “Overview of T and D-T results in JET with ITER-like wall” by CF Maggi et al. to be published in Nuclear Fusion Special Issue: Overview and Summary Papers from the 29th Fusion Energy Conference (London, United Kingdom, 16-21 October 2023)

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Phys. Rev. Research 7, L012004 – Published 8 January, 2025

DOI: https://doi.org/10.1103/PhysRevResearch.7.L012004

Abstract

This letter reports on new fundamental insights into small scale plasma turbulence that is responsible for confinement degradation on the JET tokamak. We compare the structure of electron temperature gradient (ETG) driven turbulence in the edge region of two JET ITER-like-wall (ILW) high-confinement-mode discharges operating at different levels of gas fuelling. By artificially removing the toroidal drifts from our gyrokinetic turbulence simulations, we demonstrate that the high gas pulse has a substantial component from the toroidal branch of ETG turbulence whilst the low gas pulse is completely driven by slab ETG turbulence. This enables us to explicitly answer why increased gas puffing on JET-ILW leads to confinement degradation.

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References (21)

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Phys. Rev. Research 7, L012004– Published 8 January, 2025
  • Received 22 September 2023
  • Revised 24 May 2024
  • Accepted 22 August 2024
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